Graphene means a single layer of sp2-bonded carbon atoms, and is a quasi-two dimensional material. Graphene has attracted great interests due to its unique band structure and physical properties. Graphene has excellent properties such as quantum electron transfer, an adjustable band gap, an extremely high mobility, a high elasticity, and electro-mechanical variation. Since the first discover of separated graphene that is fabricated by a mechanical exfoliation of a graphite crystal, various chemical approaches for synthesizing a large scale of graphene, including a two dimensional assembling of reduced graphene oxides and an epitaxial growth on a silicon carbide and ruthenium as well as an exfoliated graphene sheet, have been developed. A process for surface precipitation of carbons in transition metal can also form graphene structures. From recent developments in synthesis of a large scale of a graphene film on a nickel layer and a copper layer through a chemical vapor deposition method, and a subsequent etching method for removing a catalyst layer, it is expected that graphene structures will be useful for various macroscopic application such as a transparent conductive film which is flexible and tensible and can be used for an electronic device.
CVD growth of graphene on a copper foil has been known as being advantageous in terms of controlled thickness and quality, and an etching and transferring method useful and effective for an practical fabrication scale (Science 324, 1312, 2009). However, there has been limit in fabricating three dimensional graphene structures in various forms.